Closure device

ABSTRACT

The closure device includes interlocking fastening strips and a slider slidably disposed on the fastening strips for facilitating the occlusion and deocclusion of the fastening strips. The external surface of the slider is designed to alter the way in which the slider will be grasped by the user. By providing outwardly protruding surfaces on the side portions of the slider, the slider will be grasped near the front or back of the slider. Thus, the user experiences a feeling that the slider is easier to move along the fastening strips. In another embodiment, by providing a gripping surface near the top portion of the slider, the slider will be grasped near the top portion of the slider. Thus, the slider will be easier to move and the slider reduces the tearing that may result when too much pressure is applied to the bottom portion of the slider during movement of the slider.

FIELD OF THE INVENTION

The present invention relates generally to closure devices and, moreparticularly, to a slider having a shape which causes the user to gripthe slider in a predetermined manner. The invention is particularly wellsuited for flexible storage containers, including plastic bags.

BACKGROUND OF THE INVENTION

The use of closure devices for fastening storage containers, includingplastic bags, is generally known. Furthermore, the manufacture ofclosure devices made of plastic materials is generally known to thoseskilled in the art, as demonstrated by the numerous patents in thisarea.

A particularly well known use for closure devices is in connection withflexible storage containers, such as plastic bags. In some instances,the closure device and the associated container are formed fromthermoplastic materials, and the closure device and the sidewalls of thecontainer are integrally formed by extrusion as a single piece.Alternatively, the closure device and sidewalls of the container may beformed as separate pieces and then connected by heat sealing or anyother suitable connecting process. In either event, such closure devicesare particularly useful in providing a closure means for retainingmatter within the bag.

Conventional closure devices typically utilize mating fastening stripsor closure elements, which are used to selectively seal the bag. Aslider may be provided for use in opening and closing the fasteningstrips. Some of these sliders may include a separator which extends atleast partially between the fastening strips. When the slider is movedin the appropriate direction, the separator divides the fastening stripsand opens the bag.

One of the difficulties involved with using a slider is the manner inwhich the user grips the slider. Generally, the slider is gripped in thecenter. This situation requires that the slider be pulled which requiresmore force than if the slider were pushed. Additionally, if the slideris gripped towards the bottom, the shoulders of the slider may tear intothe sidewalls of the plastic container or the fastening strips.

SUMMARY OF THE INVENTION

The present invention provides a closure device with a slider having aspecific shape that results in the slider being gripped in a certainfashion. The closure device comprises first and second interlockingfastening strips arranged to be interlocked over a predetermined length.The slider is slidably disposed on the interlocking fastening strips forfacilitating the occlusion and deocclusion of the fastening strips whenmoved towards first and second ends of the fastening strips. Theexternal surface of the slider is designed to alter the way in which theslider will be grasped by the user. By providing outwardly protrudingportions on the side portions of the slider, the slider will be graspednear the front or back of the slider. Thus, the slider will be easier tomove along the fastening strips because the gripping forces by the userwill be reduced. In another embodiment, by providing a gripping surfacenear the top portion of the slider, the slider will be grasped near thetop portion of the slider. Thus, the slider will be easier to move andthe slider reduces the tearing that may result when too much pressure isapplied to the bottom portion of the slider during movement of theslider.

The present invention will become more readily apparent upon reading thefollowing detailed description of exemplified embodiments and uponreference to the accompanying drawings herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a container according to the presentinvention in the form of a plastic bag;

FIG. 2 is a perspective view of a slider;

FIG. 3 is a top view of a prior art slider being gripped by the thumband index finger of the user;

FIG. 4 is a top view of the slider in FIG. 2 being gripped by the thumband index finger of the user;

FIG. 5 is a perspective view of another embodiment of a slider;

FIG. 6 is a perspective view of another embodiment of a slider;

FIG. 7 is a perspective view of another embodiment of a slider;

FIG. 8 is a front view of the slider in FIG. 7;

FIG. 9 is a side view of the slider in FIG. 7;

FIG. 10 is a perspective view of another embodiment of a slider;

FIG. 11 is a cross-sectional view of an embodiment of fastening stripsand a slider;

FIG. 12 is a cross-sectional view of another embodiment of fasteningstrips and a slider;

FIG. 13 is a cross-sectional view of another embodiment of fasteningstrips and a slider;

FIG. 14 is a cross-sectional view of another embodiment of fasteningstrips and a slider.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 illustrates an embodiment of a container in the form of a plasticbag 120 having a sealable closure device 121. The bag 120 includes afirst sidewall 122 and a second sidewall 123 joined at seams 125, 126 todefine a compartment accessible through the open top end but sealable bymeans of the closure device 121. The closure device 121 includes firstand second fastening strips 130, 131 and a slider 132.

The fastening strips 130, 131 and the slider 132 have a longitudinal Xaxis 102, a transverse Y axis 104 and a vertical Z axis 106. Thetransverse Y axis 104 is perpendicular to the longitudinal X axis 102.The vertical Z axis 106 is perpendicular to the longitudinal X axis 102and the vertical Z axis 106 is perpendicular to the transverse Y axis104.

The slider 132 is mounted onto the fastening strips 130, 131 so that theslider 132 is restrained from being removed from the fastening strips130, 131 but free to slide along the X axis 102. The slider 132 engagesthe fastening strips 130, 131 so that when the slider 132 moves in anocclusion direction 114, the fastening strips 130, 131 interlock and thebag 120 is sealed, and when the slider 132 moves in a deocclusiondirection 116, the fastening strips 130, 131 separate and the bag 120 isopen.

FIG. 2 illustrates a perspective view of a slider that may be used withthe closure device depicted in FIG. 1. The slider 132 includes a topportion 140. The top portion 140 of the slider merges into a first sideportion 142 and a second side portion 144. The first side portion 142has a first protruding portion 150. Similarly, the second side portion144 has a second protruding portion 152. The first protruding portion150 and the second protruding portion 152 extend laterally along theouter surfaces of the side portions 142, 144 and include outwardlyprotruding radial surfaces 160, 162. The slider is wider at the centerdue to the protruding portions 150, 152 than at the front and rearportions 170, 172. The user has a tendency to grip the narrowestlocation on the slider. Therefore, due to the protruding portions 150,152 the user will grip the slider near the front and rear portions 170,172 as opposed to the center of the slider.

In the prior art, the slider is designed so that the user grips theslider 232 at the center 236 with the index finger 246 and the thumb 248when the user wishes to move the slider as shown in FIG. 3. The usermust exert both a pulling force and gripping forces. The user exertsgripping forces 251, 253 on the slider 232 at pressure areas 254, 256.In addition, the user exerts a pulling force 261 in order to move theslider 232 in the desired direction 214. The user experiences a feelingthat the slider is difficult to move because the user must exert boththe pulling force and the gripping forces in order to move the slider.

In the present invention, the slider 132 is designed so that minimumpressure or gripping forces are needed by the index finger and the thumbto grip the slider in order to move the slider along the fasteningstrips. Referring to FIG. 4, the index finger 146 and thumb 148 of theuser engage the slider 132 at the rear portion 172 due to the protrudingportions 150, 152 as noted above. When the user engages the rear portion172, the gripping forces 151, 153 needed by the index finger 146 and thethumb 148 to move the slider are very small. These gripping forces arevery small in comparison to the gripping forces required when engagingthe center of the slider. In addition, the user will exert a pushingforce 161 in order to move the slider 132 in the desired direction 114.The user experiences a feeling that the slider is easier to move becausethe user exerts less gripping forces.

FIG. 5 illustrates a perspective view of another embodiment of a slider332. The slider 332 includes first and second protruding portions 350,352 with outwardly protruding radial surfaces 360, 362 respectively. Theradial surfaces 360, 362 extend laterally along the length of the sideportions 342, 344. The protruding portions result in the slider beinggripped near the front and rear portions 370, 372 of the slider 332.Thus, the user experiences a feeling that the slider is easier to movebecause the user exerts less gripping forces as noted above.

FIG. 6 illustrates a perspective view of another embodiment of a slider432. The slider includes first and second side portions 442, 444. Thefirst side portion 442 includes a protruding portion 450 which includestwo outwardly protruding linear surfaces 464, 465. The linear surfaces464, 465 are joined at a point halfway along the side portion 442.Similarly, the second side portion 444 includes a protruding portion 452which includes two outwardly protruding linear surfaces 466, 467. Thelinear surfaces 466, 467 are joined at a point midway along the sideportion 444. The protruding portions result in the slider being grippednear the front and rear portions 470, 472 of the slider. Thus, the userexperiences a feeling that the slider is easier to move because the userexerts less gripping forces as noted above.

FIGS. 7-9 illustrate another embodiment of a slider 532. The slider 532will reduce the possibility that the shoulders of the slider will damagethe fastening strips or the sidewalls of the container. The sliderincludes a top portion 540 and first and second side portions 542, 544attached to the top portion 540. The first side portion 542 has a firstgripping surface 550 at the upper portion 551 of the slider 532.Similarly, the second side portion 544 has a second gripping surface 552at the upper portion 551 of the slider 532. The first gripping surface550 and the second gripping surface 552 may extend laterally along theouter surfaces of the side portions 542, 544. In addition, the grippingsurfaces 550, 552 may include inwardly protruding radial surfaces 560,562 designed to correspond to the contours of a person's fingertips. Theuser will have a tendency to grip the gripping surfaces 550, 552 becausethe gripping surfaces correspond to the thumb and index finger of theuser. Therefore, as shown in FIG. 9, the user will use the thumb andindex finger to apply gripping forces 570, 572 to the gripping surfaces550, 552. The gripping surfaces 550, 552 are located in the upperportion 551 of slider and near the top surface 540 of the slider. Thus,the gripping forces 570, 572 will be applied to the upper portion of theslider 532 and near the top portion 540.

When the gripping forces 570, 572 are applied near the top portion 540,the amount of deflection in the side portions 542, 544 is less than ifthe same gripping forces were applied in the lower portion of the sliderat locations 574, 576. If the gripping forces are applied at the lowerportion of the slider, the gap 580 between the side portions 542, 544reduces in size. If the size of the gap is reduced, then the fasteningstrips or sidewalls located in the gap 580 may be damaged or torn by theside portions 542, 544 or the shoulders 586, 588 during movement of theslider 532. Damage to the fastening strips or the sidewalls would beundesirable. Furthermore, if the size of the gap 580 is reduced, theside portions 542, 544 or the shoulders 586, 588 will apply more forceto the fastening strips or sidewalls which will create more friction andmake movement of the slider along the fastening strips more difficult.Therefore, by locating the gripping surfaces 550, 552 at the upperportion of the slider, the slider will cause less damage to thecontainer and the slider is easier to move along the fastening strips.

FIG. 10 illustrates a perspective view of another embodiment of a slider632. The slider includes a top portion 640, a first side portion 642 anda second side portion 644. The first side portion 642 includes twooutwardly protruding bumps 656, 657 disposed at the upper portion 651 ofthe slider 632. Similarly, the second side portion 644 includes twooutwardly protruding bumps 658, 659 disposed at the upper portion 651 ofthe slider 632. The bumps 656, 657, 658, 659 facilitate the gripping ofthe slider 632 at the upper portion of the slider 632. The bumps assistin creating a gripping surface which corresponds to the thumb and indexfinger of the user. As noted above, by locating the gripping surfaces atthe upper portion of the slider, the slider will cause less damage tothe container and the slider is easier to move along the fasteningstrips.

The slider may be multiple parts and snapped together. In addition, theslider may be made from multiple parts and fused or welded together. Theslider may also be a one piece construction. The slider can be colored,opaque, translucent or transparent. The slider may be injection moldedor made by any other method. The slider may be molded from any suitableplastic material, such as, nylon, polypropylene, polystyrene, acetal,toughened acetal, polyketone, polybutylene terrephthalate, high densitypolyethylene, polycarbonate or ABS (acrylonitrile-butadiene-styrene).

As shown in FIG. 11, the fastening strips may be U-channel fasteningstrips as described in U.S. Pat. No. 4,829,641. U-channel fasteningstrips include a first fastening strip 730 with a first closure element736 and a second fastening strip 731 with a second closure element 734.The first closure element 736 engages the second closure element 734.The first fastening strip 730 may include a flange 763 disposed at theupper end of the first fastening strip 730 and a rib 767 disposed at thelower end of the first fastening strip 730. The first fastening strip730 may include a flange portion 769. Likewise, the second fasteningstrip 731 may include a flange 753 disposed at the upper end of thesecond fastening strip 731 and a rib 757 disposed at the lower end ofthe second fastening strip 731. The second fastening strip 731 mayinclude a flange portion 769. The side walls 722, 723 of the plastic bag720 may be attached to the fastening strips 730, 731 by conventionalmanufacturing techniques.

The second closure element 734 includes a base portion 738 having a pairof spaced-apart parallely disposed webs 740, 741, extending from thebase portion 738. The base and the webs form a U-channel closureelement. The webs 740, include hook closure portions 742, 744 extendingfrom the webs 740, 741 respectively, and facing towards each other. Thehook closure portions 742, 744 include guide surfaces 746, 747 whichserve to guide the hook closure portions 742, 744 for occluding with thehook closure portions 752, 754 of the first closure element 736.

The first closure element 736 includes a base portion 748 including apair of spaced-apart, parallely disposed webs 750, 751 extending fromthe base portion 748. The base and the webs form a U-channel closureelement. The webs 750, 751 include hook closure portions 752, 754extending from the webs 750, 751 respectively and facing away from eachother. The hook closure portions 752, 754 include guide surfaces 745,755, which generally serve to guide the hook closure portions 752, 754for occlusion with the hook closure portions 742, 744 of the secondclosure element 734. The guide surfaces 745, 755 may also have a roundedcrown surface.

The slider 732 includes a top portion 772. The top portion provides aseparator 743 having a first end and a second end wherein the first endmay be wider than the second end. In addition, the separator 743 may betriangular in shape. When the slider is moved in the occlusiondirection, the separator 743 deoccludes the fastening strips 730, 731 asshown in FIG. 11. Referring to FIG. 11, the closure elements 734, 736are deoccluded and specifically, the upper hook portions 742, 752 andthe lower hook portions 744, 754 are deoccluded.

The interlocking fastening strips may comprise “arrowhead-type” or “riband groove” fastening strips as shown in FIG. 12 and as described inU.S. Pat. No. 3,806,998. The rib element 805 interlocks with the grooveelement 807. The rib element 805 is of generally arrow-shape intransverse cross section including a head 810 comprising interlockshoulder hook portions 811 and 812 generally convergently related toprovide a cam ridge 813 generally aligned with a stem flange 814 bywhich the head is connected in spaced relation with respect to thesupporting flange portion 808. (U.S. Pat. No. 3,806,998, Col. 2, lines16-23). At their surfaces nearest the connecting stem flange 814, theshoulder portions 811 and 812 define reentrant angles therewithproviding interlock hooks engageable with interlock hook flanges 815 and817 respectively of the groove element 807. (U.S. Pat. No. 3,806,998,Col. 2, lines 23-28). Said hook flanges generally converge toward oneanother and are spread open to receive the head 810 therebetween whensaid head is pressed into said groove element 807 until the head isfully received in a groove 818 of said groove element 807 generallycomplementary to the head and within which the head is interlocked byinterengagement of the head shoulder hook portions 811 and 812 and thegroove hook flanges 815 and 817. (U.S. Pat. No. 3,806,998, Col. 2, lines28-36). Through this arrangement, as indicated, the head and grooveelements 805 and 807 are adapted to be interlockingly engaged by beingpressed together and to be separated when forcably pulled apart, as bymeans of a generally U-shaped slider 819. (U.S. Pat. No. 3,806,998, Col.2, lines 36-41).

The slider 819 includes a flat back plate 820 adapted to run along freeedges 821 on the upper ends of the sections of the flange portions 808and 809 as shown in the drawing. (U.S. Pat. No. 3,806,998, Col. 2, lines41-46). Integrally formed with the back plate 820 and extending in thesame direction (downwardly as shown) therefrom are respectivecoextensive side walls 822 with an intermediate spreader finger 823extending in the same direction as the side walls at one end of theslider. (U.S. Pat. No. 3,806,998, Col. 2, lines 46-51). The side walls822 are in the form of panels which are laterally divergent from anarrower end of the slider. (U.S. Pat. No. 3,806,998, Col. 2, lines51-55). The slider walls 822 are each provided with an inwardlyprojecting shoulder structure 824 flange adapted to engage respectiveshoulder ribs 825 and 827 on respectively outer sides of the lowersection of the flange portions 808 and 809. (U.S. Pat. No. 3,806,998,Col. 2, line 66 to Co. 3, line 3).

Additionally, the interlocking fastening strips may comprise “profile”fastening strips, as shown in FIG. 13 and described in U.S. Pat. No.5,664,299. As shown in FIG. 13, the first profile 916 has at least anuppermost closure element 916 a and a bottommost closure element 916 b.(U.S. Pat. No. 5,664,299, Col. 3, lines 25-27). The closure elements 916a and 916 b project laterally from the inner surface of strip 914. (U.S.Pat. No. 5,664,299, Col. 3, lines 27-28). Likewise, the second profile917 has at least an uppermost closure element 917 a and a bottommostclosure element 917 b. (U.S. Pat. No. 5,664,299, Col. 3, lines 28-30).The closure elements 917 a and 917 b project laterally from the innersurface of strip 915. (U.S. Pat. No. 5,664,299, Col. 3, lines 30-32).When the bag is closed, the closure elements of profile 916 interlockwith the corresponding closure elements of profile 917. (U.S. Pat. No.5,664,299, Col. 3, lines 32-34). As shown in FIG. 19, closure elements916 a, 916 b, 917 a and 917 b have hooks on the ends of the closureelements, so that the profiles remain interlocked when the bag isclosed, thereby forming a seal. (U.S. Pat. No. 5,664,299, Col. 3, lines34-37).

The straddling slider 910 comprises an inverted U-shaped member having atop 920 for moving along the top edges of the strips 914 and 915. (U.S.Pat. No. 5,664,299, Col. 4, lines 1-3). The slider 910 has side walls921 and 922 depending from the top 920. (U.S. Pat. No. 5,664,299, Col.4, lines 3-4). A separating leg 923 depends from the top 920 between theside walls 921 and 922 and is located between the uppermost closureelements 916 a and 917 a of profiles 916 and 917. (U.S. Pat. No.5,664,299, Col. 4, lines 26-30). The fastening assembly includes ridges925 on the outer surfaces of the fastening strips 914 and 915, andshoulders 921 b and 922 b on the side walls of the slider. (U.S. Pat.No. 5,664,299, Col. 4, lines 62-65). The shoulders act as means formaintaining the slider in straddling relation with the fastening stripsby grasping the lower surfaces of the ridges 925. (U.S. Pat. No.5,664,299, Col. 5, lines 4-7).

Also, the interlocking fastening strips may be “rolling action”fastening strips as shown in FIG. 14 and described in U.S. Pat. No.5,007,143. The strips 1014 and 1015 include profiled tracks 1018 and1019 extending along the length thereof parallel to the rib and grooveelements 1016 and 1017 and the rib and groove elements 1016, 1017 havecomplimentary cross-sectional shapes such that they are closed bypressing the bottom of the elements together first and then rolling theelements to a closed position toward the top thereof. (U.S. Pat. No.5,007,143, Col. 4, line 62 to Col. 5, line 1). The rib element 1016 ishook shaped and projects from the inner face of strip 1014. (U.S. Pat.No. 5,007,143, Col. 5, lines 1-3). The groove element 1017 includes alower hook-shaped projection 1017 a and a relatively straight projection1017 b which extend from the inner face of strip 1015. (U.S. Pat. No.5,007,143, Col. 5, lines 3-6). The profiled tracks 1018 and 1019 areinclined inwardly toward each other from their respective strips 1014and 1015. (U.S. Pat. No. 5,007,143, Col. 5, lines 6-8).

The straddling slider 1010 comprises an inverted U-shaped plastic memberhaving a back 1020 for moving along the top edges of the tracks 1018 and1019 with side walls 1021 and 1022 depending therefrom for cooperatingwith the tracks and extending from an opening end of the slider to aclosing end. (U.S. Pat. No. 5,007,143, Col. 5, lines 26-31). A separatorfinger 1023 depends from the back 1020 between the side walls 1021 and1022 and is inserted between the inclined tracks 1018 and 1019. (U.S.Pat. No. 5,007,143, Col. 5, lines 34-36). The slider 1010 has shoulders1021 a and 1022 a projecting inwardly from the depending side walls 1021and 1022 which are shaped throughout the length thereof for cooperationwith the depending separator finger 1023 in creating the rolling actionin opening and closing the reclosable interlocking rib and grooveprofile elements 1016 and 1017. (U.S. Pat. No. 5,007,143, Col. 5, lines43-49).

The interlocking fastening strips may be manufactured by extrusionthrough a die. The interlocking fastening strips may be formed from anysuitable thermoplastic material including, for example, polyethylene,polypropylene, nylon, or the like, or from a combination thereof. Thus,resins or mixtures of resins such as high density polyethylene, mediumdensity polyethylene, and low density polyethylene may be employed toprepare the interlocking fastening strips. For example, the fasteningstrips may be made from low density polyethylene.

When the fastening strips are used in a sealable bag, the fasteningstrips and the films that form the body of the bag may be convenientlymanufactured from heat sealable material. In this way, the bag may beeconomically formed by using an aforementioned thermoplastic materialand by heat sealing the fastening strips to the bag. For example, thebag may be made from a mixture of high pressure, low densitypolyethylene and linear, low density polyethylene.

The fastening strips may be manufactured by extrusion or other knownmethods. For example, the closure device may be manufactured asindividual fastening strips for later attachment to the bag or may bemanufactured integrally with the bag. In addition, the fastening stripsmay be manufactured with or without flange portions on one or both ofthe fastening strips depending upon the intended use of the fasteningstrips or expected additional manufacturing operations.

The fastening strips can be manufactured in a variety of forms to suitthe intended use. The fastening strips may be integrally formed on theopposing sidewalls of the container or bag, or connected to thecontainer by the use of any of many known methods. For example, athermoelectric device may be applied to a film in contact with theflange portion of the fastening strips or the thermoelectric device maybe applied to a film in contact with the base portion of fasteningstrips having no flange portion, to cause a transfer of heat through thefilm to produce melting at the interface of the film and a flangeportion or base portion of the fastening strips. Suitable thermoelectricdevices include heated rotary discs, traveling heater bands,resistance-heated slide wires, and the like. The connection between thefilm and the fastening strips may also be established by the use of hotmelt adhesives, hot jets of air to the interface, ultrasonic heating, orother known methods. The bonding of the fastening strips to the filmstock may be carried out either before or after the film is U-folded toform the bag. In any event, such bonding is done prior to side sealingthe bag at the edges by conventional thermal cutting. In addition, thefirst and second fastening strips may be positioned on opposite sides ofthe film. Such an embodiment would be suited for wrapping an object or acollection of objects such as wires. The first and second fasteningstrips should usually be positioned on the film in a generally parallelrelationship with respect to each other, although this will depend onthe intended use.

From the foregoing it will be understood that modifications andvariations may be effectuated to the disclosed structures—particularlyin light of the foregoing teachings—without departing from the scope orspirit of the present invention. As such, no limitation with respect tothe specific embodiments described and illustrated herein is intended orshould be inferred. In addition, all references and copendingapplications cited herein are hereby incorporated by reference in theirentireties.

What is claimed is:
 1. A closure device, comprising: first and secondinterlocking fastening strips arranged to be interlocked over apredetermined longitudinal X axis between first and second ends, thefastening strips having a transverse Y axis, the transverse Y axis beingperpendicular to the longitudinal X axis, the fastening strips having avertical Z axis, the vertical Z axis being perpendicular to thelongitudinal X axis, the vertical Z axis being perpendicular to thetransverse Y axis; and a slider slidably disposed on the fasteningstrips for movement between the first and second ends, the sliderfacilitating occlusion of the fastening strips when moved towards thefirst end, the slider facilitating the deocclusion of the fasteningstrips when the slider is moved towards the second end, wherein theslider includes a first side portion, a second side portion and a topportion, the slider has an upper portion and a lower portion, the upperportion being adjacent the top portion, a first gripping surface islocated on the first side portion at the upper portion of the slider,the slider includes a first shoulder located on the first side portionat the lower portion of the slider, the first gripping surface and thefirst shoulder being offset from each other relative to the Z axis. 2.The invention as in claim 1 wherein the first and second side portionsare separated by a first distance when the slider is not being grippedby the user, the first distance remains substantially the same whenbeing gripped by the user to move the slider.
 3. The invention as inclaim 1 wherein the first gripping surface extends laterally along theupper portion of the slider.
 4. The invention as in claim 1 wherein thefirst gripping surface includes an inwardly protruding radial surface.5. The invention as in claim 1 wherein the first gripping surfaceextends outwardly from the first side portion.
 6. The invention as inclaim 1 wherein the first gripping surface includes two outwardlyprotruding bumps.
 7. The invention as in claim 1 wherein a secondgripping surface is located on the second side portion of the slider. 8.A container comprising: first and second sidewalls joined at seams toform a compartment with an opening; first and second interlockingfastening strips respectively connected to the first and secondsidewalls at the opening, the fastening strips arranged to beinterlocked over a predetermined longitudinal X axis between first andsecond ends, the fastening strips having a transverse Y axis, thetransverse Y axis being perpendicular to the longitudinal X axis, thefastening strips having a vertical Z axis, the vertical Z axis beingperpendicular to the longitudinal X axis, the vertical Z axis beingperpendicular to the transverse Y axis; and a slider slidably disposedon the fastening strips for movement between the first and second ends,the slider facilitating occlusion of the fastening strips when movedtowards the first end, the slider facilitating the deocclusion of thefastening strips when the slider is moved towards the second end,wherein the slider includes a first side portion, a second side portionand a top portion, a first gripping surface is located on the first sideportion of the slider, a first shoulder is located on the first sideportion of the slider, the first gripping surface and the first shoulderbeing offset from each other relative to the Z axis.
 9. A method ofmanufacturing a closure device, comprising: providing first and secondinterlocking fastening strips arranged to be interlocked over apredetermined longitudinal X axis between first and second ends, thefastening strips having a transverse Y axis, the transverse Y axis beingperpendicular to the longitudinal X axis, the fastening strips having avertical Z axis, the vertical Z axis being perpendicular to thelongitudinal X axis, the vertical Z axis being perpendicular to thetransverse Y axis; and providing a slider slidably disposed on thefastening strips for movement between the first and second ends, theslider facilitating occlusion of the fastening strips when moved towardsthe first end, the slider facilitating the deocclusion of the fasteningstrips when the slider is moved towards the second end, wherein theslider includes a first side portion, a second side portion and a topportion, a first gripping surface is located on the first side portionof the slider, a first shoulder is located on the first side portion ofthe slider, the first gripping surface and the first shoulder beingoffset from each other relative to the Z axis.
 10. A closure device,comprising: first and second interlocking fastening strips arranged tobe interlocked over a predetermined X axis between first and secondends; and a slider slidably disposed on the fastening strips formovement between the first and second ends, the slider facilitatingocclusion of the fastening strips when moved towards the first end, theslider facilitating the deocclusion of the fastening strips when theslider is moved towards the second end, wherein the slider includes afirst side portion, a second side portion and a top portion, a firstprotruding portion disposed along the first side portion of the slider,the slider has a front portion and a rear portion, the first protrudingportion causes the user to grip the slider at the front portion or atthe rear portion, the first protruding portion includes an outwardlyprotruding radial surface, the radial surface extends along the entirelength of the first side portion.
 11. The invention as in claim 10wherein the second side portion includes a second protruding portion.12. A closure device, comprising: first and second interlockingfastening strips arranged to be interlocked over a predetermined X axisbetween first and second ends; and a slider slidably disposed on thefastening strips for movement between the first and second ends, theslider facilitating occlusion of the fastening strips when moved towardsthe first end, the slider facilitating the deocclusion of the fasteningstrips when the slider is moved towards the second end, wherein theslider includes a first side portion, a second side portion and a topportion, a first protruding portion disposed along the first sideportion of the slider, the slider has a front portion and a rearportion, the first protruding portion causes the user to grip the sliderat the front portion or at the rear portion, the first protrudingportion includes two outwardly protruding linear surfaces disposed tojoin at the center of the first side portion.
 13. The invention as inclaim 12 wherein the first protruding portion extends laterally alongthe length of the first side portion.
 14. The invention as in claim 12wherein the second side portion includes a second protruding portion.